Detergent aid and method of



March 1940. H. o. MOTTERN 2,192,713

DETERGENT AID AND METHOD OF PREPARING THE SAME Filod Sept. 18, 1937 flG/T'ATOR AG/TA TOR Sol. vrlclv ourLEr AlkAL/NE SOLUTION ACID OLEFI/V REACT/01v 1 0072 Alive 12 2 CONDENSER l/AFOR L/Ive NEUTRAL/ZED SOLUTION OUTLET JPEA/T ac/o OUTLET am/yo/a mmawuw iii Patented Mar. 5, 1940- DETERGENT AID AND METHOIl OF PREPARING THE SAME Henry 0. Mottern, Elizabeth, N. J., assignor to Standard Oil Development Company, a corporation ot Delaware Application September 18, 1937, Serial No. 164,476 9 Claims. (01.260-513) v V This invention relates to improved detergent aids. By detergent aids it is intended to include wetting, dispersing, emulsifying agents and detergents. The invention particularly relates to the manufacture of these materials from by-product materials in chemical processes. It especially relates to the utilization of by-product materials having little value formed in the manufacture of alcohols, esters and ethers from olefins by converting said by-product materials to detergents of superior quality and recovering the same.

Various types of wetting, emulsifying and detergent materials are already known; however, the high quality products are relatively expensive, and the cheaper products are relatively ineflicient. In addition, the materials of this type now marketed for use as wetting agents, emulsifying agents and detergents do not have the desired stability with respect to hard water, and thus form an appreciable precipitation of insoluble matter, resulting in an undesirable scum which deposits on clothing or other material being laundered or dyed. The present invention providing for detergent aids frombyproduct materials particularly from by-product materials secured in the manufacture of alco-- hols, esters and ethers from olefins by means of sulphuric acid supplies an inexpensive, superior detergent having none of the above-mentioned disadvantages.

The invention will be more clearly understood by referring to the drawing which shows a typical. flow plan of a process from which the detergent aids of the present invention may. be secured. The process flow plan given for illustration relates particularly to the manufacture of butyl alcohol from butylenes. In this process, a raw liquid fraction, known in the petroleum industry as the butane cut, containing butylenes, which has been segregated with suitable equipment, for instance, from refinery gases which are evolved from petroleum distilling, cracking and naphtha reforming operations, is fed into agi-v tator l by means of feed line 2. Sulphuric acid of the desired strength is introduced into agitator l by means of feed line 3 and a complete mixing secured by means of the revolving stirrer l. The unreacted compounds of the butane 'cut fraction, containing admixed with the complex polymer sulphuric acid reaction products known as sulfo'acids", is withdrawn from agitator I by means of line 5 and introduced into agitator 6 where it is neutralized or sweetened by an 5 alkaline solution, such as sodium hydroxide, in-

troduced through line 1. Stirrer 8 serves to insure complete mixing and neutralization of any acid constituents. The sweetened unreacted compounds of the butane cut from which these sulio acids and entrained free sulphuric acid have been removed is taken off through line 9.

The caustic solution containing neutralized sulphuri'c acid and sulfo acids is withdrawn through line l0 and is usually regarded as awaste product. The acid olefin reaction liquor of agitator I, containing secondary butyl acid sulfate and disecondary butyl sulfate, is withdrawn through line H and introduced into hydrolyzer l2, wherein it is thoroughly mixed by means of stirrer I4 with water introduced by means of line l3. The reaction product consisting of butyl alcohol, sulphuric acid, water and complex polymer sulphuric acid reaction products known as "sulfo acids, is introduced into a steam stripping tower [6, wherein the alcohols are separated from the spent acid. The spent acid containing sulfo acids and water is with-' drawn through line 23 and is usually reconcentrated, which eliminates the water and destroys the sulfo acids. The alcohol containing sulfo acids, water and some free sulphuric acid. is taken overhead through vapor line I8 into condenser I9, in which it is neutralized by means of an alkaline solution such as sodium hydroxide fed in through line 20. The alcohol free of sulfo acids" and sulphuric acid.- is withdrawn through line 2| and is further purified. The caustic solution containing neutralized sulfo acids and sulphuric acid is withdrawn by means of line 22 and is usually discarded.

This process may be varied within wide Temperatures, pressures, acid strengths and any particular method of mixing or treating may be widely varied. The conditions, of course, change when diflerent olefins are treated and when a particular alcohol, such as tertiary butyl alcohol,

is desired. For example, in the manufacture of I isopropyl alcohols, a tower under suitable pressure is substituted for. agitator I. Thistower contains suitable bubble plates and cooling means. In the manufacture of butyl alcohols from a butane cut fraction containing butylenes, it is desirable to use a sulphuric acid concentration of about 90% and to maintain a pressure of approximately 25 pounds and a temperature of about C. in agitator I. In the manufacture of isopropyl alcohol an acid strength of about 92% is employed and tower I is maintained at a pressure of about 80 pounds per square inch gauge and at a temperature of about C. In

"the manufacture of amyl and heal alcohols somewhat lower acid concentration is used, usuand the temperature of agitator G is maintained at approximately 30 C.

Under all the varying conditions of the above processes, there is formed. complex- "sulfo aci compounds throughout the process which. are

usually discarded. It has now been found that if these sulfo acids are neutralized, segregated and purified, they have superior detergent aid properties. The usual materials from which the detergent aids of the present invention are prepared are complex olefin polymer sulphuric acid reaction products. The term sulfo acids is herein used for convenience in a generic sense, following the commonly accepted use of this term, to denote compounds formed by the combination of sulfuric acid with hydrocarbons, because the acid has a very complex action on hydrocarbons, e. g. mixtures of olefines, in forming sulfuric esters, various sulphonic acids or mixtures of these. These olefin polymers apparently react with a strong mineral acid to produce complex sulfo acids"'which, upon subsequent neutralization, give a compound which is a superior detergent. These sulfo acids are secured in processes involving the reaction of olefins having from 2 to 19 carbon atoms in the molecule as, for example, ethylene, propylene, butylene and decylene. The preferred detergents are prepared from sulfo acids formed in the treatment of olefins having from 3 to 5 carbon atoms in the molecule as, for example, propylene, butylene and amylene, such olefins being treated with sulphuric acid for the manufacture of alcohol, ether and esters. These olefins are usually secured from refining gases evolved from cracking, distilling and naphtha reforming operations. However, it is within the scope of this invention to utilize sulfo acids which are secured in the treatment of pure oleflns or mixtures of pure olefins in similar or other processes.

Some of the sulfa-acid detergent aid compounds are considered to have the following type formulae:

R a R Hydroxy-sulfo-aclds R- -cH0H LH- :Hr. :Hso.H Glyoollic sulfo-acids R-CHOH-CHOH-CHt m The above formulae in which R represents hydrocarbon radicals indicate product types formed from secondary base olefines. Other types of molecules such as tertiary mono-oleflnes, might also have been used in illustration. The suitable hydrocarbon fractions may contain substantial amounts of reactive tertiary and secondary mono-olefines, e. g., isobutylene and 2-butene. These reactive olefines are to some extent polymerlzed by sulfuric acid to form polymers which in turn become sulfonated, as for example:

etc-

The higher molecular weight sulfo-compounds formed by the reaction of the sulfuric acid with the secondary and tertiary olefin polymers dissolve in the spent naphtha, comprising hydrocarbons which are unreacted and uncombined with the sulfuric acid. These sulfo-compounds are separated from the spent naphtha. This sulfo-material is a valuable detergent aid. It has also been found that the acid liquor from the reaction of the acid with the olefins upon being treated for hydrolysis of esters to alcohols leaves dissolved in the aqueous spent solution a further quantity of sulfo-acids which can be segregated therefrom to obtain a valuable detergent aid. It is the hydroxysulfo type acids which are considered to be the best detergent aids.

The following examples are given as specific methods of making the detergent aids:

Example 1 A butane cut fraction, segregated from refinery gases by means of stabilizing equipment, had ap- This fraction was led into agitator I and treated with 65% sulphuric acid at a temperature at about20 to C. at a pressure of about 25 pounds gauge. The spent naphtha then was passed into agitator 6 and treated with 15 B.

sodium hydroxide solution. 5 gallons of the caustic solution containing neutralized sulphuric acid and sulfo acids from line It was evaporated to approximately 20% of its original volume. At

this point a gelatinous layer of crude detergent separated. To thissolution containing the saturated jelly-like layer was added approximately.

2 gallons of 91% isopropyl' alcohol which dissolved the separated material and caused the formation of an alcohol detergent-containing layer and an aqueous salt-containing layer. The alcohol layer containing the dissolved detergent was separated by decantation, then approximately 1 pound of sodium carbonate was added to the alcohol layer containing the dissolved detergent, which removed any dissolved caustic soda. The alcohol detergent containing solution was then evaporated to dryness in a drying oven, resulting in the recovery of 1 pounds of detergent per 1 gallon of caustic solution containing neutralized sulphuric acid and sulfo acids. The material had excellent detergent properties giving copious suds.

- Example 2 A pentane cut fraction segregated from refinery gases by means of suitable fractionating equipment had approximately the following analysis:

Saturated compounds. 67

this point approximately 2 gallons of 91% is'opropyl alcohol was added which dissolved a jelly-like true detergent material and caused the formation of an alcohol detergent containing Unsaturated compounds 33 arcane layer and an aqueous salt layer. The alcohol detergent containing layer was separated by decantation and then treated with approximately 1 pound of sodium carbonate, which caused the removal of any dissolved sodium hydroxide. The alcohol detergent layer was then evaporated to dryness and approximately 9 pounds per gallon of detergent were recovered. per gallon of caustic solution containing neutralized sulphuric acid and sulfo acids.

Example 3 A butane fraction having the analysis as given in Example 1 was extracted with 65% sulphuric acid and the acid layer decanted and then heated at C. This product was then neutralized with 15 B. sodium hydroxide and l'gallon evaporated to 25% of its original volume causing a gelatinous layer to form. At this point approximately 1% gallons of 91% isopropyl alcohol was added which dissolved the jelly-like detergent and caused the formation of an alcohol detergent containing layer and an aqueous salt containing layer. The alcohol detergent containinglayer was separated by decantation and was treated with sodium carbonate in order to remove any dissolved sodium hydroxide. The alcohol detergent containing layer was then evaporated to dryness in an oven and approximately 2.4 pounds of detergent was recovered per gallon of caustic solution containing neutralized sulphuric acid, sulfo acids.

The wetting number of these detergents was determined with the following result:

Wetting No. Seconds 0.2% solution in distilled water-clear, slightly straw colored 0.2% solution in hard water-Ca++300 parts/million 177 0.2% solution in acid water.3% sulphuric acid Wetting No.

Seconds 0.2% solution in distilled water-colorless 0.2% solution in hard waterCa++--300 parts/million 145 0.2% solution in acid water-3% sulphuric acid 205 "Wetting No. is measured b the disc method and represents the number of seconds i: takes for a small circular disc (2 cm. diam.) of cotton cloth to become coin letely wetted when gentl laid on the surface of an 0.2 a solution of the soap 11 water.

Example d Spent acid, as from line 23, was chilled to 0-5 C. and allowed to stand until the sulfo acids were precipitated as a flocculent solid. The sulfo acids" were filtered from the spent acid (10-20%) and then taken up in 91% isopropyl alcohol. The alcohol solution was neutralized with sodium hydroxide and then sep- The above examples are merely given by way of illustration. Other methods of purification may be employed, such as evaporating the neutralired "sulfo acids" sulphuric acid solutions to dryness, followed by separating the sulfo acid salt from the mineral salts and other impurities with a suitable solvent such as alcohol. Although it is preferred to add the alcohol to the evaporated caustic solution containing as a precipitate the jelly-like detergent in order to dissolve the detergent and then ,to separate, the detergent may be separated by decantation from the salt solution before the addition of alcohol in which it is dissolved.

The sulfo acids may be secured at any stage of the process, for instance, the sulfo acids may be segregated in the manufacture of alcohol from the spent acid which is at the present time reconcentrated. This acid may b chilled to precipitate the "sulfo acids, as described in Example 4, or the acid neutralized and the sulfo salts segregated in the manner outlined above i. e. by evaporating the caustic solution to 20 to 40% of its volume and then adding alcohol to dissolve the gelatinous layer which forms, followed by 'decantation of the alcohol detergent containing layer.

The invention is not to be limited in any manner by the examples given or by any theory as to the method of production, but only by the following claims in which it is desired to claim all novelty in so far as the prior art permits.

I claim:

1. Process for producing detergent aids comprising treatinga low-boiling mono-olefin with sulphuric acid to secure a product comprising alkyl sulfates, "sulfo acids" and unreacted sulphuric acid, separating the resulting acid and hydrocarbon phases, hydrolyzing the alkyl sulfates in each phase, heating the resulting aqueous solutions to concentrate therein the sulfo-acid compounds, separating said compounds and extracting purified sulfo-acid compounds with an organic solvent.

2. Process of producing detergent aids comprising treating a low-boiling mono-olefin with sulphuric acid to secure a product comprisng alkyl sulfates, sulfo acids and unreacted sulphuric acid, separating the resulting acid and hydro= carbon phases, hydrolyzing the alkyl sulfates in the acid phase to secure an oxygenated product of the class consisting of alcohols, ethers, esters and acids, separating the two phases thus formed, neutralizing the acids in the two phases and recovering the sulfo-acid compounds from one of 1 the two phases by extraction with an organic solvent and subsequent evaporation.

3. Process in accordance with claim 2 in which said oxygenated products are separated from the sulphuric acid phase, neutralized with an Y the alkaline solution separated and evaporated to approximately 20 to 40% of its original volume causing the precipitation of a neutralized sulfo aci product, a sufficient quantity of alcohol added to dissolve the said neutralized sulfo acid" product, followed by separation and evaporation of the alcohol to recover the detergent aids.

4. Process in accordance with claim 2 in which the sulphuric acid phase is neutralized with an alkaline solution, the neutralized solution evaporated to approximately 20 to 40% of its original volume causing the precipitation of a neutralized sulfo acid" product, a sufficient quantity of alcohol added to dissolve the said neutralized sulfo acid" precipitate, followed by the removal and evaporation of the alcohol layer to recover the neutralized sulfo acid product.

5. Process in accordance with claim 2 in which the sulphuric acid phase is chilled to a temperature below 0 C. causing the precipitation of the "sulfo acids, filtering the sulphuric acid to recover the precipitated sulfo acidsfl'dissolving the precipitated sulfo acids in alcohol and neutralizing with a sodium hydroxide solution, followed by the separation and evaporation of the alcohol layer to recover the neutralized sulfo' acids.

6. Process of producing detergent aids comprising treating a normally gaseous hydrocarbon olefin-containing fraction with sulphuric acid to form a product comprising alkyl sulfates, *sulfo acids", unreacted hydrocarbons and sulphuric acid, separating the unreacted hydrocarbons, hydrolyzing the alwl sulfates to form oxygenated a product of the class consisting of alcohols, ethers and esters, separating the unreacted hydrocarbon phase, hydrolyzing the alkyl sulfates therein to form an oxygenated product of the class consisting of alcohols, ethers, esters and acids, separating from the predominantly acid phase said oxygenated products, neutralizing the acids in the two phases and recovering the sulfoacid compounds from one of the two phases by extraction with an organic solvent and subsequent evaporation.

8. Process in accordance with claim 7 in which the sulfo acids" are neutralized and recovered from one of the separated fractions by treating said fraction with an alkaline solution, separating and evaporating said alkaline solution to approximately 20 to 40% of'its original volume causing the precipitation of the neutralized sulfo acld'. product, adding a sufiicient quantity of alcohol to dissolve the neutralized sulfo acid precipitate, followed by removal and evaporation of the alcohol layer to recover the neutralized sulfo acid'materials. v

9. Process in accordance with claim 7 in which said sulfo acids are neutralized and recovered from one of the separated fractions by chilling the acid' to a temperature below 0 C., causing the precipitation of the sulfo acids, filtering the acid .to recover the precipitated sulfo acids", dissolving the precipitated sulfo acids in alcohol and neutralizing the solution with sodium hydroxide, followed by separation and evaporation '01 the alcohol layer to recover the neutralized sulfo acids.

HENRY O. MOTI'ERN. 

